The present disclosure relates to a toner conveying unit and an image forming apparatus including the same suitably used in a copier, a printer and the like.
There is known an image forming apparatus including a toner case configured to store toner and an intermediate transfer unit provided between the toner case and a developing unit disposed below the toner case. The image forming apparatus adopting such electro-photographic technology is configured to form a color toner image by sequentially transferring each color toner image formed on a plurality of image carriers disposed in tandem to an intermediate transfer belt in the intermediate transfer unit. The image forming apparatus forms a color image on a sheet by transferring the color toner image on the intermediate transfer belt to the sheet.
There is also known an image forming apparatus including a toner cartridge including a shutter member or the like opening/closing a toner replenishing port and a sheet conveying belt (intermediate transfer belt) carrying a color toner image for example. Such image forming apparatus includes a toner conveying path for supplying toner from a toner case to a developing unit. This arrangement makes it possible to equalize length of the toner conveying paths and to suppress the apparatus from being enlarged.
However, although it is possible to close the replenishing port of the toner cartridge by the shutter member in replacing (removing) the toner cartridge, no consideration has been made on closing an upper opening (toner inlet) of the toner conveying path communicating with an upper opening of the developing unit or the developing unit in the image forming apparatus described above. In this case, because the toner inlet is always opened, toner flies from the toner inlet and contaminates around the toner inlet in removing/attaching the toner case.
The intermediate transfer unit in which the toner conveying path is formed also often requires to manually open/close a lower opening (toner outlet) of the toner conveying path in replacing the toner case. In such a case, a user is forced to separately carry out opening/closing operations of the toner inlet and toner outlet, and is unable to readily replace toner cases.